Blade sharpeners

ABSTRACT

Blade sharpeners are disclosed that have at lease one abrasive wheel of cylindrical section and blade supports at both of its sides tapering towards the axis thereof for supporting one face of a double bevelled cutting edge with its other face against the proximate wheel side. The sharpeners are either of the free rolling type or are rotatably mounted in a support. The sharpeners have removable covers, each cover provided with a slot to receive a blade having a single bevel cutting edge and support it with its bevelled face tangentially engaging the periphery of the subjacent wheel. When the sharpeners include two axially aligned wheels, the abrasive of one is finer than that of the other.

United States Patent Thompson 1 Mar. 114, 11972 [54] BLADE SHARPENERS [21] Appl. No.: 30,746

[56] References Cited UNITED STATES PATENTS 1,092,877 4/1914 Wallace ..51/210 1,773,564 8/1930 Witzleben. 2,114,106 4/1938 Geveke ..51/2l0X 2,469,797 5/1949 Thompson ..51/2l0 Primary Examiner-Donald G. Kelly Attorney-Abbott Spear [57] ABSTRACT Blade sharpeners are disclosed that have at lease one abrasive wheel of cylindrical section and blade supports at both of its sides tapering towards the axis thereof for supporting one face of a double bevelled cutting edge with its other face against the proximate wheel side. The sharpeners are either of the free rolling type or are rotatably mounted in a support. The sharpeners have removable covers, each cover provided with a slot to receive a blade having a single bevel cutting edge and support it with its bevelled face tangentially engaging the periphery of the subjacent wheel. When the sharpeners include two axially aligned wheels, the: abrasive of one is finer than that of the other.

14 Claims, 10 Drawing Figures PATENTEDMAR m I972 3, EMA 1 d sum 2 [1F 2 BLADE SHARPIENEIRS BACKGROUND OF THE INVENTION Wherever edged implements are used there is a need for a sharpening device, particularly in households where, usually, there is a wide range of edged implements of which knives and scissors are the most common examples. Householders, as a general rule, are not adept in the use of whetstones and, in recognition of that fact, many different types of edge sharpeners have been made available to the public that are easier to use.

Among such sharpeners, those made in accordance with my US Pat. No. 2,469,797 of May 10, 1949, have been well accepted and effective in use. Such sharpeners are of a freerolling type with supports on both sides of an abrasive wheel engageable by one face of a double bevelled blade thus to hold the other face of the cutting edge against the proximate face of the abrasive wheel so that it is only necessary to reciprocate the blade forwardly and rearwardly to roll the sharpener back and forth with the turning abrasive wheel subjecting the cutting edge of the thus supported blade to an effective sharpening treatment. Such sharpeners are more effective when made in accordance with my US. Pat. No. 3,238,673 of March 8, 1966, whether of the free rolling type or rotatably supported by a holder, since it provides for vertical movements of the blade against the side of the abrasive wheel as it is moved forwardly and rearwardly.

Such sharpeners do not, however, meet all requirements. In the first place, they are essentially adapted for use in sharpening blades having a double bevelled cutting edge. In the second place, many implements become quite dull before an attempt is made to sharpen them. In practice, such dull blades require first a treatment with a relatively coarse abrasive and another treatment with a relatively fine abrasive. The first treatment is important as it enables the correct bevel to be quickly established, the subsequent treatment by the finer abrasive preparing the cutting edge for its intended uses. Treatment with the coarse abrasive is incapable of producing a satisfactory cutting edge and treatment with a fine abrasive by itself is too slow for use in providing a cutting edge if the cutting edge is deformed to any substantial extent. In addition, even if two sharpening devices are available, one with a relatively fine abrasive and the other with a relatively coarse abrasive, neither is readily distinguishable from the other unless a side-by-side use is provided for.

SUMMARY OF'THE INVENTION One general objective of the present invention is to provide sharpeners enabling cutting edges of both the oppositely bevelled and the single bevel types to be effectively sharpened, an objective attained with sharpeners having at least one abrasive wheel and supports for maintaining either face of a double-bevelled edge in a position in which its other bevelled face is against the proximate face of the wheel. The sharpeners are either free rolling or rotatably mounted in a holder. In either case, the sharpeners are provided with removable covers, each having a slot to receive a blade having a single bevelled cutting edge and support it with its bevelled face tangential to the periphery of the abrasive wheel. In the free rolling type, the cover fits the supporting rollers and holds them against rotation with its margins engaging the surface on which the sharpener rests. In the latter case, the cover is detachably attached to the holder in which the sharpener is rotatably supported and also engages with portions thereof to hold its abrasive wheel or wheels from turning.

Another general objective of the invention is to provide sharpener units, either with or without covers and either free rolling or held captive sharpener units in which two abrasive wheels are axially connected with the abrasive of one being finer than that of the other and with each wheel having a blade support at each side thereof and, as both abrasive wheels are exposed to the user, he can shift quickly from one to the other in proper sequence with the wheel having the coarser abrasive enabling the bevels to be quickly restored and the finer abrasive ensuring their being accurately finished for use.

In the accompanying drawings, embodiments of the invention are shown that are illustrative of these and other of its objectives, novel features, and advantages.

In the drawings:

FIG. 1 is a plan view of a sharpener in accordance with one embodiment of the invention;

FIG. 2 is a section, on an increase in scale, taken approximately along the indicated lines 2--2 on FIG. 1 and, illustrating the sharpening of a blade whose cutting edge is defined by a single bevel;

FIG. 3 is a perspective view of the sharpener illustrating the reversibility of the cover;

FIG. 4 is a plan view of a sharpener in accordance with another embodiment of the invention;

FIG. 5 is an end view of the sharpener of FIG. 4;

FIG. ti is a perspective view thereof;

FIG. 7 is a side view of a cover having an adjustable blade support;

FIG. 8 is a view similar to FIG. 2 but with the cover removed and reattached to serve as a handle for the sharpener while sharpening a blade whose cutting edge is defined by a double bevel;

FIG. 9 is a like view but illustrating the use of the unit as a free-rolling sharpener; and

FIG. 10 is a section taken approximately along the indicated lines 10-10 ofFIG. 9.

A sharpener unit, generally indicated at 15, is shown in the embodiment of the invention illustrated by FIGS. 1-3 and 8, as axially supported within a generally indicated holder 16 by pivots 17 carried by the holder end walls 18. In the embodiment of the invention illustrated by FIGS. 4, 5, 9, and 10, the sharpener unit 15 is provided with a removable holder or cover 19. While the sharpener units for both types of sharpeners are not necessarily identical, the use of the same unit for both types is economically advantageous and is preferred.

Each sharpener unit 15 has a pair of abrasive wheels 20 and 21, one on each side of an intermediate member 22 and both shown as of cylindrical section. The abrasive of the wheel 20 is, however, finer than that of the wheel 21. Each wheel has, see FIG. 2, an axial recess 23 in each face and these are interconnected by an axial passage 24. End roller members 25 have their rims provided with rubber tread bands 26 and axial stems 27 shown, see FIG. 10, as square in cross section, with their corner-to-corner dimension being such that they may be entered through the axial passage 24 of an abrasive wheel. The free end of each stem 27 has a socket 28 receiving a threaded axial anchor 29 by which it is connected to the intermediate member 22.

The sharpener unit 10 also includes blade supports 30, one for each side of each abrasive wheel. Each support 30 has a flanged outer edge 31 dimensioned to receive a peripheral margin of either of the roller members 25 or of the intermediate member 22 and an oppositely disposed hub 32 through which a stem 27 extends and which is with its extremity dimensioned to fit snugly in and engage with an abrasive wheel recess 23. With this construction, the roller and intermediate members, the abrasive wheels, and the blade supports become securely interconnected to establish a sharpening unit 15 in which the abrasive wheels cannot be independently turned. The hub 32 of each blade support 30 is downwardly inclined towards its recess-entering end at an angle relative to the proximate side of the proximate abrasive wheel appropriate for the support of one beveled face of the double bevelled cutting edge of a blade 33 when the other bevelled face of that cutting edge is face-to-face contact with that hub see FIGS. 8 and 9.

Turning now to the holder 16, it will be noted, see FIG. 8, that there is a clearance between the end walls 18 and its side walls 34 and the pivot axis of the unit 15 is above the upper edges of the side walls 34. The holder 16 is provided with a U- shaped cover 35 having inturned end tabs 36 engageable with the outer surface of the end walls 18, the upper parts of each end wall 18 being slightly inclined towards the other to facilitate the attachment of the cover 35. The cover 35 has a transverse slot 37 inclined relative to the axis of the unit and of such width that a blade 38 having its cutting edge defined by a single bevel, a scissors blade, for example, may be entered with the bevelled face tangentially engaging the periphery of the subjacent abrasive wheel. It will be noted, see FIG. 2, that when the cover 35 is attached it engages the bands 26 of the end roller members and thus prevents the unit 15 from turning as the blade 38 is reciprocated. It will also be noted, see FIG. 3, that when the cover is removed, it may be re-attached in a reversed position exposing the other abrasive wheel under the slot 37 for engagement by that or another blade of the same type.

With the cover removed, see FIG. 8, the sharpener is ready for use in sharpening the blade 33, preferably with the cover 35 attached to one end wall 18, then to function as a handle. The clearance between the end and the side walls permits the slidable entry of the tabs 36 into a position engaging the inner face of either end wall adjacent the bottom of the holder 16. In practice, the bevelled faces of the cutting edge are first treated by the abrasive wheel 21 to re-establish their bevels and is then shifted to be treated by the abrasive wheel 20 to finish the sharpening of its edge. This is effectively accomplished because of the re-establishment of correct bevels ensuring the effectiveness of the hubs 32 in holding the blade 33 while its edge is being finished by the finer abrasives.

The holder or cover 19, as will be seen from FIGS. 5 and 6, is centrally curved for engagement with the roller members 25 of a unit 15 with its sides curving inwardly towards each other to ensure such resilient roller engagement that the unit 15 is prevented from turning. The sides then curve outwardly to provide rubber-faced marginal supports 39. The cover 19 has a slot identical to the slot 37 of the cover 35 and supporting a blade such as the blade 38 in the previously described manner with respect to the subjacent abrasive wheel while the blade 38 is being reciprocated. It will be appreciated that the cover 19 is easily removed and may be replaced in a reversed position to expose the other abrasive wheel for use.

With the cover 19 detached, the unit 15 becomes a sharpener of the free rolling type, see FIGS. 9 and 10. With a blade 33 positioned on one side of one of the abrasive wheels with a bevelled face in contact therewith and pushed back and forth, the sharpener unit 15 rolls forwardly and rearwardly over the supporting surface. Desirably, but not necessarily, the blades having bevelled faces to be sharpened against the side of the abrasive wheels are supported in accordance with U.S. Pat. No. 3,238,673. To this end, the hubs 32 are shown as square in cross section as but one example of a shape that will cause the reciprocated blade also to move upwardly and downwardly against the engaged face of the abrasive wheel, see FIG. 10, whether the sharpener 15 is held captive or is free to roll on the supporting surface.

As there is a wide range of bevel angles in the case ofimplements whose cutting edges are established by a single bevel, a holder 41 is shown in FIG. 7 as having a slot 42 permitting access to the subjacent abrasive wheel and provided with a support 43 connected to the holder 41 by pivots 44. The support 43 is adjustable to establish a desired angular relationship between it and the periphery of the abrasive wheel and the pivot 44 shown in FIG. 7 has a wing nut 45 threaded thereon to enable the established position of the support 43 to be maintained during the use of the sharpener 15 then contained within it.

It will be apparent from the foregoing that sharpeners in accordance with the invention are well adapted to meet a wide range of edge sharpening requirements without the necessity of maintaining at hand a plurality ofsharpening devices.

I claim:

1. A sharpener for a blade having an edge defined by op positely bevelled sides, said sharpener comprising an abrasive wheel of cylindrical section, end roller members, and an axial connection between said wheel and said members, the face of each member disposed towards said wheel including a blade support tapering inwardly towards the wheel axis at an acute angle relative to the proximate wheel face appropriate for supporting one bevelled blade face with its other bevelled face against said proximate wheel face, and a removable cover for said sharpener engaging said end members and holding them against turning, said cover having a slot to receive a blade having its cutting edge defined by a single bevel with said bevel in tangential engagement with the periphery of said abrasive wheel.

2. The sharpener of claim 1 in which the cover slot is shaped and dimensioned to hold the blade in a predetermined position.

3. The sharpener of claim 1 and a support pivotally secured to the cover and adjustable to establish a selected angular relation between it and the periphery of the abrasive wheel.

4. The sharpener of claim 1 in which the removable cover is in the form of a clip of a length sufficient to engage the rollers members, the major portion of the clip being so curved as to provide frictional engagement with the major portion of the periphery of the roller members, the margins of the clip being oppositely disposed to provide supports for the sharpener when placed on a flat surface.

5. The sharpener of claim 1 and a support including end walls, pivot means axially connect the sharpener to the end walls, and the cover is detachably attached to the support.

6. The sharpener of claim 1 and a support including end and side walls, pivot means axially connect the sharpener to the end walls, the cover includes end tabs engageable with the outer faces of the end walls, and there are vertical slits between at least one end wall and the proximate ends of the side walls which slidably receive the tabs at one end of the cover thus to attach the cover to the end of the support then to function as a handle.

7. A sharpener for a blade having an edge defined by oppositely beveled sides, said sharpener comprising a pair of abrasive wheels of cylindrical section, the abrasive of one wheel being finer than the abrasive of the other, end roller members, an intermediate member, the end roller members being of greater diameter than the abrasive wheels and the intermediate member, and an axial connection between said wheels and said members, one wheel between each end member and the intermediate member, the face of each member disposed towards a wheel including a blade support tapering inwardly towards the wheel axis at an acute angle relative to the proximate wheel face appropriate for supporting one beveled blade face with its other beveled face against said proximate wheel face, each roller member including an axial stem extending axially through an appropriate one of the abrasive wheels and the axial connection is a threaded connection between each stem and the intermediate member.

8. The sharpener of claim 7 in which the abrasive wheels are so spaced that the cover may have two positions of attachment, one a reversal of the other, in either position, a selected one of the wheels being exposed under the slot.

9. The sharpener of claim 8 and a removable cover engaging said end members and holding them against turning, said cover having a slot dimensioned to receive a blade having its cutting edge defined by a single bevel to hold that blade at an angle such that its bevel tangentially engages the periphery of one abrasive wheel.

10. The sharpener of claim 9 in which the cover has two positions of attachment to the sharpener, in each of which the end members are engaged with a different one of the abrasive wheels accessible through the slot to a blade having a single bevel.

11. The sharpener of claim 9 in which the cover is in the form of a clip of resilient material of a length sufficient to engage the roller members, the major portion of the clip being so curved as to provide frictional engagement with the major portion of the periphery of the roller members, the margins of the clip being oppositely disposed to provide supports for the through its slot when reattached.

13. The sharpener of claim 12 in which the cover is in the form of a clip of resilient material and frictionally engages the sides of the support.

14. The sharpener of claim 13 in which the cover also has inturned end tips engageable with the outer faces of the end walls. 

1. A sharpener for a blade having an edge defined by oppositely bevelled sides, said sharpener comprising an abrasive wheel of cylindrical section, end roller members, and an axial connection between said wheel and said members, the face of each member disposed towards said wheel including a blade support tapering inwardly towards the wheel axis at an acute angle relative to the proximate wheel face appropriate for supporting one bevelled blade face with its other bevelled face against said proximate wheel face, and a removable cover for said sharpener engaging said end members and holding them against turning, said cover having a slot to receive a blade having its cutting edge defined by a single bevel with said bevel in tangential engagement with the periphery of said abrasive wheel.
 2. The sharpener of claim 1 in which the cover slot is shaped and dimensioned to hold the blade in a predetermined position.
 3. The sharpener of claim 1 and a support pivotally secured to the cover and adjustable to establish a selected angular relation between it and the periphery of the abrasive wheel.
 4. The sharpener of claim 1 in which the removable cover is in the form of a clip of a length sufficient to engage the roller members, the major portion of the clip being so curved as to provide frictional engagement with the major portion of the periphery of the roller members, the margins of the clip being oppositely disposed to provide supports for the sharpener when placed on a flat surface.
 5. The sharpener of claim 1 and a support including end walls, pivot means axially connect the sharpener to the end walls, and the cover is detachably attached to the support.
 6. The sharpener of claim 1 and a support including end and side walls, pivot means axially connect the sharpener to the end walls, the cover includes end tabs engageable with the outer faces of the end walls, and there are vertical slits between at least one end wall and the proximate ends of the side walls which slidably receive the tabs at one end of the cover thus to attach the cover to the end of the support then to function as a handle.
 7. A sharpener for a blade having an edge defined by oppositely beveled sides, said sharpener comprising a pair of abrasive wheels of cylindrical section, the abrasive of one wheel being finer than the abrasive of the other, end roller members, an intermediate member, the end roller members being of greater diameter than the abrasive wheels and the intermediate member, and an axial connection betWeen said wheels and said members, one wheel between each end member and the intermediate member, the face of each member disposed towards a wheel including a blade support tapering inwardly towards the wheel axis at an acute angle relative to the proximate wheel face appropriate for supporting one beveled blade face with its other beveled face against said proximate wheel face, each roller member including an axial stem extending axially through an appropriate one of the abrasive wheels and the axial connection is a threaded connection between each stem and the intermediate member.
 8. The sharpener of claim 7 in which the abrasive wheels are so spaced that the cover may have two positions of attachment, one a reversal of the other, in either position, a selected one of the wheels being exposed under the slot.
 9. The sharpener of claim 8 and a removable cover engaging said end members and holding them against turning, said cover having a slot dimensioned to receive a blade having its cutting edge defined by a single bevel to hold that blade at an angle such that its bevel tangentially engages the periphery of one abrasive wheel.
 10. The sharpener of claim 9 in which the cover has two positions of attachment to the sharpener, in each of which the end members are engaged with a different one of the abrasive wheels accessible through the slot to a blade having a single bevel.
 11. The sharpener of claim 9 in which the cover is in the form of a clip of resilient material of a length sufficient to engage the roller members, the major portion of the clip being so curved as to provide frictional engagement with the major portion of the periphery of the roller members, the margins of the clip being oppositely disposed to provide supports for the sharpener when placed on a flat surface, the cover being reversible to expose the other abrasive wheel through its slot when reattached.
 12. The sharpener of claim 9 and a support including end walls, pivot means axially connect the sharpener to the end walls, and the cover is of a length sufficient to engage the roller members and dimensioned to engage the support, the cover being reversible to expose the other abrasive wheel through its slot when reattached.
 13. The sharpener of claim 12 in which the cover is in the form of a clip of resilient material and frictionally engages the sides of the support.
 14. The sharpener of claim 13 in which the cover also has inturned end tips engageable with the outer faces of the end walls. 